The Present Application relates, generally, to a card connector, and, more particularly, to a card connector having a braking force of an appropriate magnitude that can be constantly stably exerted at an appropriate timing regardless of the dimensional accuracy of the memory card, and thus, the card can be stably and certainly ejected at an appropriate speed while preventing the card from springing out from the card connector.
Typically, an electronic device is provided with a card connector in order to use a variety of memory cards. From the viewpoint of usability, recent card connectors typically have a push-push structure that requires an operation of pushing a memory card when the memory card is inserted therein and ejected therefrom. However, in a push-push type card connector, since the card is slid by a repulsive force of a spring generated when the card is ejected, the moving speed of the card or a slide member holding the card becomes rather high, so that there might occur an unfavorable state such that the card springs out of the card connector or the slide member collides against a stopper member and an impact is applied thereto. In this regard, a proposal has already been made to provide a technique that uses a decelerating device to decelerate the card or the slide member when the card is ejected. An example of a typical card connector is disclosed in Japanese Patent Application No. 2007-015039.
FIG. 10 is an exploded perspective view of a card connector according to the prior art. Referring to FIG. 10, a housing of a card connector, which is formed of an insulating material such as synthetic resin, is generally designated by reference numeral 811, and is provided with plurality of connection terminals 851 which is formed of metal. A shell of the card connector, which is formed of a metal plate, is generally designated by reference numeral 861, and is attached to an upper side of housing 811. Memory card 901 is inserted into a space defined between shell 861 and housing 811, so that non-illustrated contact pads of memory card 901 come into contact with corresponding connection terminals 851.
In the example illustrated in the drawing figure, the card connector is a so-called push-push type connector, and is provided with a guide mechanism for permitting ejection of memory card 901 therefrom. The guide mechanism is provided with slide member 821 configured to be engaged with memory card 901 to slide together with memory card 901 and coil spring 881 that urges slide member 821 in a direction for ejecting memory card 901.
Guide mechanism-accommodation groove portion 811h is formed in one side portion of housing 811, so that slide member 821 is slidably accommodated in guide mechanism-accommodation groove portion 811h. Cam groove 823 of a heart cam mechanism is provided on an upper surface of slide member 821, and one end of pin member 871 of the heart cam mechanism is provided to be engaged with cam groove 823. The other end of pin member 871 is provided for being locked in guide mechanism-accommodation groove portion 811h at a position in the vicinity of stopper portion 811g. Pin member 871 is held by being urged downward from an upper side by leaf spring member 865 of shell 861.
Slide member 821 is further provided with first engagement portion 821c configured to come into engagement with a front end of memory card 901, projecting portion 824 configured to come into engagement with a front end of convex engagement portion 911 of memory card 901, second engagement portion 821d configured to come into engagement with concave engagement portion 912 of memory card 901, and abutting portion 821e configured to come into contact with stopper portion 811g so as to stop slide member 821.
When a user inserts and pushes memory card 901 into housing 811, memory card 901 is pushed into an innermost side of housing 811. Then, first engagement portion 821c, projecting portion 824, and second engagement portion 821d of slide member 821 come into engagement with the front end, convex engagement portion 911, and concave engagement portion 912 of memory card 901, respectively. Slide member 821 is inwardly moved toward the innermost side of housing 811 together with memory card 901 while resisting against a repulsive force of coil spring 881. Further, when one end of pin member 871 is latched to cam groove 823 by the action of the heart cam to result in stopping of slide member 821, memory card 901 comes to stop there under a state where it is inserted into housing 811.
Next, when the user pushes memory card 901 to eject the memory card 901 out of housing 811, one end of pin member 871 is released from the state of being latched to cam groove 823. With this operation, slide member 821 is set free and is therefore moved toward the front side together with memory card 901 by the force exerted by coil spring 881, and thus, memory card 901 is ejected from housing 811.
Guide mechanism-accommodation groove portion 811h is formed, in a side wall thereof, with cantilever-like brake shoe 819 having restoring properties. Moreover, upwardly pressing springs 852R, 852L are arranged on both sides of plurality of connection terminals 851. A top surface of brake shoe 819 is pressed against a side surface of projecting portion 824 of slide member 821, and the upper surfaces of upwardly pressing springs 852R, 852L are pressed against a lower surface of memory card 901.
As a result, the moving speed of slide member 821 and memory card 901 is reduced by brake shoe 819 and upwardly pressing springs 852R, 852L when memory card 901 is ejected from housing 811. Therefore, memory card 901 is prevented from springing out of the card connector, and/or abutting portion 821e of slide member 821 is prevented from colliding against stopper portion 811g while mitigating occurrence of a shock.
Nevertheless, in the above-mentioned conventional card connector, since upwardly pressing springs 852R, 852L need to be provided as additional separate members, it may lead to an increase in the number of components and in the manufacturing cost. Moreover, in recent years, with the fast trend toward lowering the manufacturing cost, the finishing accuracy of the outline of memory card 901 tends to decrease and the dimensional accuracy of the top surface of memory card 901 also tends to decrease. That is to say, even an identical type of memory cards 901 often exhibits a change in thickness dimension thereof as well as in the degree of surface roughness or smoothness thereof. For this reason, if memory card 901 has a large thickness dimension, the pressing force of upwardly pressing springs 852R, 852L becomes stronger while causing an increase in a braking force beyond an expected value. As a result, the ejection of memory card 901 is apt to be prevented. On the other hand, if memory card 901 has a small thickness dimension, the pressing force of upwardly pressing springs 852R, 852L is weakened while reducing the braking force to a value below the expected value. As a result, memory card 901 may spring out from the card connector. Similarly, if the top surface of memory card 901 is rough, a large braking force beyond the expected value appears, so that the ejection of memory card 901 is prevented. On the other hand, if the top surface of memory card 901 is smooth, the braking force becomes smaller than the expected value, so that memory card 901 may spring out from the card connector.
Brake shoe 819 needs to be provided with the restoring properties and be formed into a cantilever-like shape in the side wall of guide mechanism-accommodation groove portion 811h. On the other hand, in recent years, with the rapid miniaturization of electronic devices or apparatuses, memory card 901 and card connectors have become rapidly miniaturized. For this reason, it may be extremely difficult to form brake shoe 819 having a very small size, capable of constantly exerting stable spring characteristics, and having an extremely complicated cantilever-like shape, in the side wall of guide mechanism-accommodation groove portion 811h of housing 811 that is manufactured by integral molding with an insulating material such as synthetic resin; even if possible, it must bring about an increase in the manufacturing cost.